Introduction of three sealing parts of instrument pipe valve

The sealing performance of instrument pipe valve refers to the ability of each sealing part to prevent medium leakage. There are three sealing parts of instrument pipe valve: ① the contact surface between the opening and closing parts and the two sealing surfaces of valve seat. ② Packing and valve stem and stuffing box match and place. ③ The joint between valve body and valve cover. The leakage of valve seat sealing surface of instrument pipe is called internal leakage. It is usually said that if it is not closed tightly, it will affect the medium cutting function of instrument pipe valve. For block valves, internal leakage is not allowed. The leakage of packing and valve cover of instrument pipe valve is called external leakage, that is, the medium leaks from inside to outside of the valve. Leakage will cause material loss, pollute the environment, and even cause accidents. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the instrument pipe valve must have reliable sealing performance.